Gadsden Purchase

Gadsden Purchase, also called Treaty of La Mesilla,
(Dec. 30, 1853), transaction that followed the conquest of much of northern Mexico by the United States in 1848. Known in Mexican history as the sale of the Mesilla Valley, it assigned to the United States nearly 30,000 additional square miles (78,000 square km) of northern Mexican territory (La Mesilla), now southern Arizona and southern New Mexico, in exchange for $10,000,000. Prompted in part by advocates of a southern transcontinental railroad, for which the most practical route would pass through the acquired territory, the purchase was negotiated by the U.S. minister to Mexico, James Gadsden. Residents of the territory were to enjoy the same protections as those afforded to residents of the area ceded to the United States earlier by the Treaty of Guadalupe Hidalgo (1848).

Click anywhere inside the article to add text or insert superscripts, subscripts, and special characters.
You can also highlight a section and use the tools in this bar to modify existing content:

Add links to related Britannica articles!
You can double-click any word or highlight a word or phrase in the text below and then select an article from the search box.
Or, simply highlight a word or phrase in the article, then enter the article name or term you'd like to link to in the search box below, and select from the list of results.

Note: we do not allow links to external resources in editor.
Please click the Web sites link for this article to add citations for
external Web sites.